Sun visor extension



FIG. 1 is a front elevational view of a sun visor extension showing our new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a side view, taken from the left side of FIG. 1, the right side view being a mirror image thereof; and,

FIG. 4 is a bottom plan view thereof, the top plan view being a mirror image thereof. 

The ornamental design for a sun visor extension, as shown and described. 